Leather-finishing method and composition



Patented Apr. 14, 1931 UNITED STATES JOSEPH T. BURKE, OF CAMDEN, NEWJERSEY LEATHER-FINISHING METHOD AN D COMPOSITION No Drawing.

The present invention relates to an improved composition and process for finishing hides and skins in the preparation of leather.

The process of this invention eliminates, by a single operation, two customary steps of (1) subjecting the skins after tanning and coloring to a treatment with a fat liquor usually composed of egg yolk, salt, soap and various oils, and thereafter (2) subjecting the skins to an oil or glycerine composition or emulsion, preparatory to drying and mechanical processing.

The present invention is distinguished from the customary method in that after the loose dyes have been Washed from the skins, in the coloring drum, the skins are subjected, while in the drum, to the action of my improved composition which combines in one step the so-called fat liquor treatment as well as the oiling-off treatment.

My improved finishing and softening co1npound consists of a solution of Epsom salts, hydrochloric acid, and sulphonated neatsfoot oil.

In carrying out the invention, the skins are suitably tanned and colored. Some free dye usually remains and this is removed from the skins by a water wash while the skins 0 remain in the drum. Thereafter there is run into the drum a suitable amount of my preparation which consists, as stated, of

Epsom salts, hydrochloric acid, and sulphonated neats-foot oil.

The function of this finishing solution is to bring the hide or skin from its hard and fibrous condition back to its original soft fiber state. 7

It is believed that the Epsom salts in the solution have the effect of counter-acting or removing from the hide all impurities left as a result of the tanning operation and restore the hide to its original condition. The hydrochloric acid appears to neutralize any salts present and to render the hide or skin firm. The neats-foot oil overcomes any tendency toward dryness.

In other Words, the Epsom salts is em ployed for its cleaning qualities and also serves to counteract any acid condition pres- Application filed July 22,

1930. Serial No. 469,932.

ent in the leather, thus having the effect of purifying the skin or hide and produce a nice, smooth grain leather. In the use of hydrochloric acid, any tendency of the skins to become piped or present an undesirable softness is eliminated.

The solution comprises six ounces of Epsom salts, one-half ounce of hydrochloric acid, one and one-half ounces sulphonated neats-foot oil, and one and one-half gallons of clear water. Hence with a six hundred pound drum, which is a regular size, the solution should comprise twelve pounds of epsom salts, sixteen ounces of hydrochloric acid, and three pounds of sulphonated neats-foot oil 55 mixed with forty-eight gallons of clean water heated to a temperature of 110 F.

After mixing, the solution is run into the drum containing the skins and after about thirty minutes the skins may be taken out and are ready for their mechanical process.

It will be understood that the finishing step takes place in the coloring or tanning drum and that it is not necessary to remove the skins from such drum. This in itself is a considerable saving in both time and expense and the present solution, since it combines and improves the function of the fat liquor step and the oiling-off step common with present procedure, enables a consiclerable saving to be effected in the finishing of the hides or skins. This is due primarily to the fact that with present finishing processes the steps must be accomplished by removing the skin or hide from the coloring drum and, 55 moreover, two or more finishing solutions are resorted to and which of themselves are considerably more expensive than the simple solution which I have found most effective.

I have had some success with Glauber salts 99 but prefer Epsom salts as the finish obtained is decidedly more acceptable.

Vhile I have set forth sulphonated neatsfoot oil, sulphonated castor oil has proven to be an equally effective substitute.

Hydrochloric acid is apparently the best acid for the purpose, although I have found other acids of the halogens suitable.

I claim:

1. The process of finishing hides and skins which comprises tanning and coloring the hides, removing free color, and sub ecting the skin to a finishing and softening solution comprising Epsom salts, hydrochloric acid and sulphonated neats-foot oil.

' 2. The process of finishing hides and skins which comprisestanning and coloring the skins in: a suitable drum, washing out free color While permitting the hides and skins; to

remain in the drum,,2tnd adding to the drum :1, finishing and softening solution compris ing Epsom salts, hydrochloricacid, and sulphonated neats-footfoil'.

3. A finishing compoundfor hides and skins comprising Epsom salts, hydrochloric acid; and sulphonated: neats-foot 'oil;

LA finishing; compound for hides and skins comprising the: ingredients, in substantiztl lyth'e' following proportions: 6 ounces 7 ounces sulphona-ted s lons; clear water. J

my hand;

Epsom salts, 1/ ounce hydrochloric acid, 1

ncats-foot' oil, 1 gal- I. In. testimony whereof I have hereunto set JOSEPH T. BURKE; 

